Meeting Abstract
The current physiological diversity reflects a temporal moment of the entirety of life history, and “species” that are recognized as discrete units actually represent a continuum of biological forms and functions linked to each other through space and time. Closely related species are more similar due to a recent divergence, while those more distantly related tend to share functional dissimilarities. Thus, physiological characteristics observed in living species can be inherited directly from their ancestors, without an ad hoc environmental reason. Thereby, the evolutionary process generates two statistical implications in the comparative physiology: the non-configuration of “species” as statistically independent units, and the correlation between physiological traits and historical patterns of speciation. In the scientific literature regarding crustaceans, physiological data sets derived from multiple species have been traditionally interpreted as “states matched to specific environmental conditions”, evoking adaptation and propagating bias in designating natural selection as the formative agent of better organic horizons. Such traditional thinking suggests that a graduated series of successively stronger adaptive mechanisms may have driven habitat diversification, however such linking becomes questionable and may hold true only in specific cases after considering the phylogenetic history. Here, I illustrate such epistemological understanding using osmoregulation and metabolism in decapod crustaceans from tropical to sub-Antarctic South America, and from marine to fresh water and terrestrial travelers. I will exhibit how a hierarchical perspective on physiological diversity can answer evolutionary questions and reexamine old paradigms.
